Polyoxymethylene compositions containing ethylene/vinyl ester copolymers

ABSTRACT

Synthetic fibres, films &amp;c. containing a polyoxymethylene are made by shaping a mixture of (A) 10 to 98% by weight of a high molecular weight polyoxymethylene and (B) 90 to 2% by weight of a substance of melting point below 250 DEG  C., which substance may be (i) a homopolymer, (ii) a copolymer with another copolymerizable monomer, (iii) a homopolymer or copolymer saponification product, (iv) a homopolymer or copolymer saponification product derivative (or two or more of types (i) to (iv)) of an organic acid vinyl ester.  The polyoxymethylene may have a molecular weight of at least 10,000.  Its terminal -OH groups may be modified by esterification, etherification or urethanization.  Substance (i) may be chosen from list A or from list B.  Substance (iii) may be a saponification product of a substance of List A or List B. Substance (iv) may be chosen from list C.  In examples polyoxymethylene diacetate is used and in one example polyoxymethylene dimethyl ether mixed with benzalized polyvinyl alcohol.  In the examples in which polyoxymethylene diacetate is used the other component is either formalized ethylenevinylacetate copolymer, polyvinyl alcohol which has been reacted with formaldehyde and -aminobutyraldehyde, formalized polyvinyl alcohol, polyvinyl formate, or an ethylene-vinyl alcohol copolymer.

United States Patent 3,310,608 POLYOXYMETHYLENE COMPOSITIONS CON- TAINING ETHYLENE/ VINYL ESTER C0- POLYMERS Kanji Matsubayashi, Kenichi Tanabe, and Osamu Fukushima, Kurashilti, Japan, assignors to Kurashiki Rayon Company Limited, Kurashiki, Japan, a corporation of Japan No Drawing. Filed May 29, 1962, Ser. No. 198,480 Claims priority, application Japan, June 10, 1961,

adjusting the crystallization of polyoxymethylene. The quantity of organic acid vinyl ester polymers to be added with polyoxymethylene may be suitably selected, yet 2 to 90% by weight of the total polymers are preferable and at less than 2% the remarkable improvement in the dyeability and transparency cannot be expected, while at above 90% hot water resistance becomes poor, more particularly, the use as synthetic fibers is considerably limited. Thus, 5 to 60% is most desirable range and within the range synthetic fibers or other shaped articles 11 havlng mechanical PIOPGIUGS. similar to those of the heretofore known synthetic fibers or other shaped articles The present invention relates to a method of manuof polyoxymethylene and moreover, having remarkably facturing synthetic fibers. and other shaped articles of improved transparency and dyeability as well as thermal polyoxymethylene characterized in that a melt of mixture 5 stability can be easily prepared. consisting of high molecular weight polyoxymethylene The effects obtainable by the invention will be explained and a polymer, or copolymer, or saponified product, or more clearly by means of some examples. Polyoxymethylderivative thereof, of organic acid vinyl esters having ene diacetate and a mixture of it with formalized product melting point lower than 250 C., is spun or molded. of copolymerized saponified product of ethylene vinyl The principal object of. the invention is to produce acetate (15 mol percent ethylene, 50 mol percent formal) easily and at a lower cost synthetic fibers and shaped were melt-spun respectively and further heat stretched. articles of polyoxymethylene having the same mechanical The properties of thus obtained samples are shown in properties as the synthetic fiber and other shaped articles Table 1, which clearly shows that the samples B and C of heretofore known polyoxymethylene and moreover of the invention have excellent dyeability and transhaving improved dyeability and transparency. parency.

TABLE 1 Polyoxy- Saponified formal- Dry heat Shrinkage methylene ized product of Tenacity Elongation softening Dyed (percent) in Sample diacetate ethylene vinyl (g./d.) (percent) temperature 1 Transparency quantity 2 water at (percent) acetate copolymer C.) 100 0.

(percent) 1 10% shrinkage temperature.

2 Quantity of dyestufi in mg./1 g. filament when dyed with 3% Diacelliton Fast Brilliant Blue-BF (0.1. Disperse Blue 3) at 95 0. for two hours.

The shaped articles, particularly fibers, of high molecular weight polyoxymethylene have excellent dimen- 4O sional stability, high tenacity and high elasticity. However their transparency and dyeability are too poor to be used commercially, though they can be obtained at low cost.

It has been found that the mixture of high molecular weight polyoxymethylene and vinyl ester polymer described above can be melt-spun or molded, because of their good miscibility, and fibers, films and other shaped articles manufactured from said mixture are remarkably improved in transparency and dyeability to disperse dye and other various kinds of dyestuif without lowering desirable properties such as tenacity, elasticity and dimensional stability of high molecular weight polyoxymethylene.

Further it has been proved that the improvement in the dyeability becomes more remarkable and at the same time the thermal stability of polyoxymethylene can also be improved by using suitable derivatives, such as nitrogen containing derivative of organic acid polyvinyl esters or copolymers of organic acid vinyl esters, suchas urethanization product due to the reaction of urea and polyvinyl alcohol, partially saponified polyvinyl acetate, polyvinyl formal, cthylenevinyl' alcohol copolymer, or carbamoyl ethyl'atedproduct due to the reaction with acrylamide, or amino acetalized product due to the reaction with aminoaldehyde.

The reason why such remarkable effects could be found by the invention is not yet sufiiciently clear but it may be considered that the combination of polymers, copolymer, or saponified product or derivative thereof of organic acidvinyl esters with polyoxymethylene is specially effective and this is due to the fact that they have mutually moldable effect for a certain extent, thereby properly The mixing of these polymers is carried out mechanically using powders, or further kneaded together by using a hot roller or an extruder, or they may be mixed by such means that either one or both of these polymers are dissolved and mixed in a solvent, such as cresol, dimethylformamide or benzyl alcohol and then the solvent may be removed by such means as reprecipitation or evaporation. The spinning is usually effected by extruding the melt of a mixture of these polymers melted usually at a temperature above C. and below 350 C. in a vapor, such as air or nitrogen through spinnerets. Socalled semi-melt spinning may be carried out by adding a small amount of solvent or plasticizer for both of these polymers and the molding can be effected by a conventional process, such as extrusion molding, injection molding, or hot press. After the spinning or molding, if necessary, it may be subjected to stretching or heat-set treat? ment at a temperature above room temperature andbelow the melting point.

According to the invention, high molecular weight polyoxymethylene having at least 10,000 molecular weight may be used and more particularly, it is preferable to use such polyoxymethylene which has been improved in its thermal stability by esterification, etherification or urethanization of hydroxyl group at the end.

As organic acid vinyl esters use is made of vinyl acetate, vinyl forrnate, vinyl propionate, vinyl butyrate, vinyl laurate, vinyl stearate, vinyl oleate, vinyl benzoate, vinyl monochloroacetate, isopropenyl acetate, allyl acetate.

As copolymers thereof use is made of copolymer of these organic acid vinyl esters with each other or with ethylene, propylene, vinyl chloride, vinylidene chloride, styrene, methyl acrylate, acrylonitrile, methacrylonitrile,

N-vinylpyrrolidone, acrylamide, methacrylamide, methyl metha-crylate, ethyl methacrylate, methylvinyl ketone, allylchloride, 2- or 4-vinyl pyridine, 2-methyl-5-vinyl pyrid-ine, 5-ethyl-2-vinyl pyridine, allyl amine, allyl cyclohexyl amine, diethylaminoethyl methacrylate, acrylic acid, methacrylic acid, allylsulfonic acid, vinylsulfonic acid, p-styrenesulfonic acid or salts thereof. By partially or completely saponifyin-g the above substances with an alkali or an acid the saponified substances can be obtained. As derivatives, acetalized products by means of aldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, nonylaldehyde, chloroacetaldehyde, benzaldehyde, O- or p-chlorobenzaldehyde, naphthaldehyde, a aminoacetaldehyde, c dimethylaminoacetaldehyde, B-aminopropionaldehyde, ,B-aminobutyraldehyde, [3-cyclohexylaminobutyraldehyde, B-dirnethylaminobutyraldehyde, dimethylaminopivaldehyde, dicthylaminopivaldehyde, cyanoacetaldehyde, acetylarninoacetaldehyde, N-acetyl-N-cyclohexylaminobutyraldehyde, Ot-Slllfoacetaldchyde, fisulfobutyraldehyde; esterified products with organic acids such as formic acid and acetic acid; etherified products with acrylonitrile, acrylamide, ethylene oxide, propylene oxide, epichlorohydrin, l-diethylamino-2,3-epoxypropane, ,B-propiolactone, ethyleneimine, vinylsulfonic acid; and urethanized products with phenyl isocyanate, phenyl urea and urea may be used, and such polymers having melting point lower than 250 C. are desirable.

The invention will be explained further in detail by means of examples.

Example 1 Ethylene-vinyl acetate copolymer (15.1 mol percent ethylene) was saponified in methanol containing caustic soda of equivalent to vinyl acetate and then acetalized in an aqueous solution containing 100 mol percent (based on vinyl alcohol) of formaldehyde and 15% sulfuric acid at 70 C. for 2 hours, then the degree of formalization was 49.6 mol percent. 10 g. of the formalization product thus obtained and 90 g. of polyoxymethylene diacetate (having intrinsic viscosity of 1.7 dl./g. and 60 C. in chlorophenol containing 2% of oc-pinene) are mixed and dissolved in dimethylformamide, and then poured into water to precipitate the mixed polymer and after drying it was charged into an extruder having 11 mm. inner dia. and while melting at 200 C. it was extruded into air through a spinneret having 10 holes each 0.3 mm. dia. and the filaments were wound up at a speed of 250 m./min. and stretched for 350% at 130 C. The filament thus obtained is as shown by sample B in Table 1 having considerably improved dyeability and transparency if compared with the sample A (polyoxymethylene alone).

Example 2 In Example 1, 30 g. of saponified formalization product of ethylene vinyl acetate copolymer and 70 g. of poly-, oxymethylene diacetate were used and similarly treated, then the sample is as shown in Table 1, sample C having splendid transparency and particularly excellent dyeability.

I Example 3 A mixed solution containing 5% of polyvinyl alcohol having degree of polymerization 1,700, 100 mol percent of formaldehyde and mol percent of [3-aminobutyraldehyde dimethyl acetal and 5% of sulfuric acid were agitated for 2 hours at 70 C. and after the formed precipitate was washed with Water, it was boiled in dilute ammonia water to eliminate the combined sulfuric acid, then it showed the degree of formalization of 67 mol percent and the degree of amino acetalization of 6 mol percent. The product was mixed with polyoxymethylene diacetate same as in Example 1 at the ratio of :75 and sufliciently pulverized to a size less than meshes. This material was clamped between hot plates at 180 C. and pressed under the pressure of 39 kg./cm. then substanmade of polyoxymethylene alone could not be dyed at all.

Example 4 Instead of the mixed acetalization product of formaldehyde and amino aldehyde in Example 3, formalized polyvinyl alcohol having degree of formalization of 65 mol percent was used and subjected to the similar treatment, then the film was obtained which can be dyed densely with dispersion and direct dyestuffs.

Example 5 Instead of saponified formalization product of ethylenevinyl acetate copolymer in Example 1, ethylene-vinyl acetate copolymer containing 50 mol percent ethylene was used and the filament having good dyeability and transparency was obtained.

Example 6 Instead of saponified formalization product of ethylenevinyl acetate copolymer in Example 2, polyvinyl formate was used and the filament having excellent dyeability was obtained.

Example 7 Instead of saponified formalization product of ethylenevinyl acetate copolymer in Example 2, ethylene-vinyl a1- cohol copolymer containing 21.5 mol percent of ethylene was used and filament having excellent dyeability was obtained.

Example 8 A mixture of 40 g. of benzalized polyvinyl alcohol having the degree of benzalization of 59 mol percent and 60 g. of polyoxymethylene dimethyl ether was hot pressed at 200 C., then the film which is transparent and dyeable with dispersion dye was obtained.

What we claim is: p

1. A method of manufacturing shaped articles of im proved transparency which comprises mixing (1) high molecular weight polyoxymethylene having a molecul ai. weight of at least 10,000 and (2) a polymer having a rnelt= ing point below 250 C. selected from the group consisting of ethylene-vinyl acetate copolymers, the saponification products thereof, and formalized saponification products thereof, to form a mixture, and extruding said mixture to form said shaped articles therefrom.

2. A method as defined in claim 1,-wherein said shaped articles are fibers.

3. A method as defined in claim 1, wherein said shaped articles are films.

4. A method as defined in claim 1, wherein said polymer comprises 2 to of said mixture. 5. A method as defined in claim 1, wherein said polymer is an ethylene-vinyl acetate copolymer.

6. A composition of matter of improved transparency consisting essentially of (1) high molecular weight polyoxymethylene having a molecular weight of at least 10,000 and (2) 2 to 90% of a polymer having a melting point below 250 C. selected from the group consisting of ethylene vinyl acetate copolymers, the saponification products thereof, and formalized saponification products thereof.

7. A shaped article of improved transparency consisting essentially of a blend of (1) high molecular weight polyoxymethylene having a molecular weight of at least 10,000- and (2) 2 to 90% of a polymer having a melting point below 250 C. selected from the group consisting of ethylene vinyl acetate copolymers, the saponification products thereof, and formalized saponification products there- 1y of a .blend of (1) high molecular weight polyoxymethylene having a molecular weight of at least 10,000 and (2) 2 to 90% of a polymer having a melting point below 250 C. selected from the group consisting of ethylene vinyl acetate copolymers, the saponification products threeof, and formalized saponification products thereof.

9. A film of improved transparency consisting essentially of a blend of (1) high molecular weight polyoxymethylene having a molecular weight of at least 10,000 and (2) 2 to 90% of a polymer 'having a melting point below 250 C. selected from the group consisting of ethylene vinyl acetate eopolymers, the saponification products thereof, and formalized saponification products thereof.

10. Fibers as defined in claim 8, wherein said polymer is an ethylene-vinyl acetate copolymer.

11. A shaped article as defined in claim 7, wherein said polymer is an ethylene-vinyl acetate copolyrner.

References Cited by the Examiner UNITED STATES PATENTS 1,985,993 1/ 1935 Herrmann et al 260 874 3,219,727 11/1965 Kray et a1 260874 3,226,455 12/ 1965 Matsubayashi et al. 26 0-897 MURRAY THJLMAN, Primary Examiner. T. G. FIELD, J. W. SANNER, Assistant Examiners. 

6. A COMPOSITION OF MATTER OF IMPROVED TRANSPARENCY CONSISTING ESSENTIALLY OF (1) HIGH MOLECULAR WEIGHT POLYOXYMETHYLENE HAVING A MOLECULE WEIGHT OF AT LEAST 10,000 AND (2) 2 TO 90% OF A POLYMER HAVING A MELTING POINT BELOW 250*C. SELECTED FROM THE GROUP CONSISTING OF ETHYLENE VINYL ACETATE COPOLYMERS, THE SAPONIFICATION PRODUCTS THEREOF, AND FORMALIZED SAPONIFICATION PRODUCTS THEREOF. 